Option to ignore white-space while merging branches

This issue has nothing to do with BCLOUD-6024 and BCLOUD-3812. Because it is not related to diff viewer, rather it is related to providing an option while merging. Though it is not duplicate of BCLOUD-6024 and BCLOUD-3812, hopefully it should still provide workaround for those.

Provide options (checkboxes) for ignoring white-space characters on merge screen (https://bitbucket.org/user/repo/branch/develop?dest=master) and pull-request screen (https://bitbucket.org/user/repo/pull-request/new?source=user/repo%3A%3Adevelop&dest=user/repo%3A%3Amaster). Basically, option for git merge -Xignore-space-change and/or git merge -Xignore-all-space

Steps to reproduce

1. Make changes in two different branches in a way that it creates conflicts (white-space conflicts only)
2. Try to merge one into other (https://bitbucket.org/user/repo/branch/develop?dest=master)

Actual result:
It can't merge due to white-space conflicts

Expected result:
It should allow to ignore white-space conflicts

Same applies for pull-requests.